Electric heating device



L. T. WEIDRICK. ELECTRIC HEATING DEVICE. APPLICATION FILED JUNE3, 192:.

Patented Oct. 17, 1922 2 SHEETSSHEET l.

L. T. WEIDRICK. ELECTRIC HEATING DEVICE.

APPLICATION FILED JUNE 3 I921- 1,432,505. w Patented 001: 17,1922

2 SHEETSSHEET 2- Patented Oct. 17, 1922.

ammo s n-res- LOUIE 'r. WEIDRICK, or BALTIMORE, MARYLAND.

Emcmm HEATING nn'v'rcn.

application filed June 3,

To all whom ii /nay concern:

Be it known that I, Lorne T. lVninnIoK, a citizen of the United States of America, residing in the city of Baltimore, State of Maryland, have invented certain new and useful Improvements in Electric Heatin Devices, of which the following is a'speci cation. 7

The present invention relates to a check or grid system for heating or preheating 2111' or gases which may be used in connection with stoves, blast furnaces, gas plants, open hearth steel furnaces" and the like. More particularly the invention relates to means for increasing the heat production of an electric arc and conveying or impart ng the lieat units thus produced to a current of air gases or other non-conducting fluid which may be passed through the heating un t or grid which is the subjectof the lnvention.

The embodiment of the invention described and illustrated herein consists of an electric arc in which is inserted a grid or check system resembling the ordinary fire brick grid used in preheating air for blast furnaces, steel mills and the like, the structure being varied for adaptation to the present invention by the substitution for a portion of the grid between the terminals of the arc of a number of bricks composed of a resistive carbon composition whichv composition may be similar to that of which the ordinary electric furnace terminals are made.

In the accompanying drawing I have illustrated a heating grid embodying my invention in what is at present considered the preferred form. I

Figure l is a section illustrating the s: ngle arc construction of furnace;

I Figure 2 is a corresponding sec-tion il-- lustrating a two are furnace;

Figure 3 is a perspective of a carbon brick of the kind used in the furnace structure illustrated.

Referring to the drawings by numerals, the structure shown consists of an air passage 1, enclosed within suitable masonry walls 2, and having openings or recesses 3, l, preferably at opposite sides in which the terminals 5, 6, illustrated in the form of adjustable carbon pencils are placed; the adjusting means consists of pencil carriers 7, 8, each of which is provided with a screw clamp 9, adapted to hold the pencil and a threaded opening 10 which receives and engages a swiveled feed screw 11., mounted 1921. Serial No. 474,725.

parallel to the pencil and extending between brackets 14,15, on a suitable base, 16. The brackets let and 15 are provided with rotary bearings 17, for screws 11, and the base is slotted at 18 parallel to the screw to receive the tail 19 of the carrier to which an electric transmission wire 20, is connected. The tail and slot serve to uide the carrier and in connection with the screw to provide suitable feed for the pencil which is clamped in the opposite end of the carrier. In the form illustrated each of the feed screws 11 is provided at one end with a knurled head 21, which projects through the cover 22, one of which covers is provided in form of invention shown for each terminal opening a, 4.

In the form of the invention illustrated I have provided carbon pencils 25, 26, cooperating with each of said adjustable carbon pencils 5 and 6 respectively, the carbon pencils 25 and 26-are in the form of invention shown each inserted in a suitable opening 21, 28, in a corresponding carbon brick 29, 30. The pencils 25, 26, are either in direct electrical contact or within arcing distance of the cooperating pencils 5, 6, the spacing beinga matter of adjustment by means of the screws 11. The bricks 29, 30, which will be referred to as the contact bricks are connected by a series of carbon bricks 32, set in checkerboard or check arrangement, meaning that they are so set as to leave a rectangular opening between each group of four bricks after well known manner as illustrated, The series of carbon bricks shown is expanded near the center at right angles to the line connecting the contact bricks and tapers down. to the contact bricks. The exact arrangement is not, however, essential to the operativeness of: the invention.

In Figure 2 I have illustrated a structure whichcorresponds exactly to the brick structure illustrated in Figure 1 except that there are four terminals or two pairs of terminals 40, 4C1, 42 and 43, of exactly the same individual arrangement as that illustrated in Figure 1 and the group 44 of carbon bricks includes four terminals 45,46,417, 48, corresponding to the pencils and the group of carbon bricks is correspondingly tapered to these four terminals.

In both embodiments of the invention the carbon bricks are surrounded and supported by fire bricks 49 similarly arranged, i. e., in a checker board pattern providing space between. the bricks. in this connection it is important to note that no particular manner oil. arrangement oil? the carbon bricks is essen ti o] to the invention, the important point being that they are arranged to provide spaces or passage ways between bricks.

in Figure 3 l have illustrated a single carbon brick 50, preferably of the composition referred to in the preamble, i. e., of the carbon composition used in electric furnace terminals and adapted for use in the structure illustrated.

In the operation of the invention the arcs are suitably adjusted preferably as illustrated by moving the pencils back and forth by means of the adjusting screws; and the carbon bricks are heated from the arcing of the current at the terminals and by the resistance to the passage of the current offered by the carbon brick structure, the fire bricks being understood to be non-conducting. In this way the carbon bricks may be brought to a white heat, a corresponding temperature being communicated to the fire bricks. lhe grid may be brought to a temperature at which it serves most effectually to heat the current of air, gases or vapor passing through it to any desired corresponding temperature, depending upon the rate oi? flow of the gases and hence to the volume of gas heated.

The heating unit described may be utilized as a preheating device for blast furnaces, steel mills, or the like or as a stove or for heating air or gas for any purpose. The multiplication of terminals and the length of the grid at right angles to the flame of the sections illustrated may be increased to any desired extent with a correspondingly increased heating effect.

I have thus described a single embodyment of my invention specifically and in detail in order that the nature and operation of same may be clearly understood to enable those skilled in the art to practice the inrention. llowevcr, the specific terms herein are used descriptively rather than in a limit ing sense, the scope oi the invention being defined in the claii'ns.

W hat I claim and, desire to secure by Letters Patent is:

1. An electric heating device consisting of a group of carbon bricks arranged in the thereof.

2. An electric heating device consisting oi a group of carbon bricks ar'anged in the form of a grid, an electric circuit, a plurality oij arcing gaps, the circuit being ar ranged to include the grid and the arcing gaps, the latter being connected to the grid near opposite sides thereotl and means for adjusting said arcing gaps.

3. An electric heating device including a carbon grid, an electric circuit including the grid and an arcing gap immediately adjacent said grid.

4-. A checker board grid for heating air or gas passing through the grid, the grid consisting of overlapping blocks with spaces between the blocks the same being iii-checker board arrangement, the grid including a. group of blocks of carbonaceous material and blocks composed of vitreous, non-con ducting material surrounding and supporting said carbonaceous blocks, means for passing a current through the carbonaceous blocks including an arcing gap adjacent the carbonaceous blocks. 7

A checker board grid for heating air or gas passing through the grid, the grid consisting of overlapping-blocks with passages between the blocks the same being in c iecker board arrangement, the grid includa group of blocks of carbonaceous material and blocks composed of vitreous, nonconducting material. surrounding and supporting said carbonaceous blocks, means for passing-a current through the carbonaceous blocks, including a plurality of arcing gaps substantially on opposite sides of the carbonaceous blocks.

{3. An electric heating unit comprising a grid composed of blocks 01' carbonacebus n'iaterial arranged in overlapping relation with spaces between the blocks.

Signed by me at liillbllllhl'v, Md, this 28th day ojl May, '1 921.

Witnesses: H

PORTER H. FLA'UTT, CARRIE M. Runny. 

